SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e484ded9c01a35f52e00d403bf75bd1b402b5623df4449accd7f8252af03191' 
  AND token = 'qPvlYEY+j4DrCDgHYV1pPFUPJmJgSEMB61bxB6CO2nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}